Date Format Cache
//
// Copyright 2004-2005 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
import java.text.DateFormatSymbols;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
/* ------------------------------------------------------------ */
/** Date Format Cache.
* Computes String representations of Dates and caches
* the results so that subsequent requests within the same minute
* will be fast.
*
* Only format strings that contain either "ss" or "ss.SSS" are
* handled.
*
* The timezone of the date may be included as an ID with the "zzz"
* format string or as an offset with the "ZZZ" format string.
*
* If consecutive calls are frequently very different, then this
* may be a little slower than a normal DateFormat.
*
* @author Kent Johnson <KJohnson@transparent.com>
* @author Greg Wilkins (gregw)
*/
public class DateCache
{
private static long __hitWindow=60*60;
private static long __MaxMisses=10;
private String _formatString;
private String _tzFormatString;
private SimpleDateFormat _tzFormat;
private String _minFormatString;
private SimpleDateFormat _minFormat;
private String _secFormatString;
private String _secFormatString0;
private String _secFormatString1;
private boolean _millis=false;
private long _misses = 0;
private long _lastMinutes = -1;
private long _lastSeconds = -1;
private String _lastResult = null;
private Locale _locale = null;
private DateFormatSymbols _dfs = null;
/* ------------------------------------------------------------ */
/** Constructor.
* Make a DateCache that will use a default format. The default format
* generates the same results as Date.toString().
*/
public DateCache()
{
this("EEE MMM dd HH:mm:ss zzz yyyy");
getFormat().setTimeZone(TimeZone.getDefault());
}
/* ------------------------------------------------------------ */
/** Constructor.
* Make a DateCache that will use the given format
*/
public DateCache(String format)
{
_formatString=format;
setTimeZone(TimeZone.getDefault());
}
/* ------------------------------------------------------------ */
public DateCache(String format,Locale l)
{
_formatString=format;
_locale = l;
setTimeZone(TimeZone.getDefault());
}
/* ------------------------------------------------------------ */
public DateCache(String format,DateFormatSymbols s)
{
_formatString=format;
_dfs = s;
setTimeZone(TimeZone.getDefault());
}
/* ------------------------------------------------------------ */
/** Set the timezone.
* @param tz TimeZone
*/
public void setTimeZone(TimeZone tz)
{
setTzFormatString(tz);
if( _locale != null )
{
_tzFormat=new SimpleDateFormat(_tzFormatString,_locale);
_minFormat=new SimpleDateFormat(_minFormatString,_locale);
}
else if( _dfs != null )
{
_tzFormat=new SimpleDateFormat(_tzFormatString,_dfs);
_minFormat=new SimpleDateFormat(_minFormatString,_dfs);
}
else
{
_tzFormat=new SimpleDateFormat(_tzFormatString);
_minFormat=new SimpleDateFormat(_minFormatString);
}
_tzFormat.setTimeZone(tz);
_minFormat.setTimeZone(tz);
_lastSeconds=-1;
_lastMinutes=-1;
}
/* ------------------------------------------------------------ */
public TimeZone getTimeZone()
{
return _tzFormat.getTimeZone();
}
/* ------------------------------------------------------------ */
/** Set the timezone.
* @param timeZoneId TimeZoneId the ID of the zone as used by
* TimeZone.getTimeZone(id)
*/
public void setTimeZoneID(String timeZoneId)
{
setTimeZone(TimeZone.getTimeZone(timeZoneId));
}
/* ------------------------------------------------------------ */
private void setTzFormatString(final TimeZone tz )
{
int zIndex = _formatString.indexOf( "ZZZ" );
if( zIndex >= 0 )
{
String ss1 = _formatString.substring( 0, zIndex );
String ss2 = _formatString.substring( zIndex+3 );
int tzOffset = tz.getRawOffset();
StringBuffer sb = new StringBuffer(_formatString.length()+10);
sb.append(ss1);
sb.append("'");
if( tzOffset >= 0 )
sb.append( '+' );
else
{
tzOffset = -tzOffset;
sb.append( '-' );
}
int raw = tzOffset / (1000*60); // Convert to seconds
int hr = raw / 60;
int min = raw % 60;
if( hr < 10 )
sb.append( '0' );
sb.append( hr );
if( min < 10 )
sb.append( '0' );
sb.append( min );
sb.append( '\'' );
sb.append(ss2);
_tzFormatString=sb.toString();
}
else
_tzFormatString=_formatString;
setMinFormatString();
}
/* ------------------------------------------------------------ */
private void setMinFormatString()
{
int i = _tzFormatString.indexOf("ss.SSS");
int l = 6;
if (i>=0)
_millis=true;
else
{
i = _tzFormatString.indexOf("ss");
l=2;
}
// Build a formatter that formats a second format string
// Have to replace @ with ' later due to bug in SimpleDateFormat
String ss1=_tzFormatString.substring(0,i);
String ss2=_tzFormatString.substring(i+l);
_minFormatString =ss1+(_millis?"'ss.SSS'":"'ss'")+ss2;
}
/* ------------------------------------------------------------ */
/** Format a date according to our stored formatter.
* @param inDate
* @return Formatted date
*/
public synchronized String format(Date inDate)
{
return format(inDate.getTime());
}
/* ------------------------------------------------------------ */
/** Format a date according to our stored formatter.
* @param inDate
* @return Formatted date
*/
public synchronized String format(long inDate)
{
long seconds = inDate / 1000;
// Is it not suitable to cache?
if (seconds<_lastSeconds ||
_lastSeconds>0 && seconds>_lastSeconds+__hitWindow)
{
// It's a cache miss
_misses++;
if (_misses<__MaxMisses)
{
Date d = new Date(inDate);
return _tzFormat.format(d);
}
}
else if (_misses>0)
_misses--;
// Check if we are in the same second
// and don't care about millis
if (_lastSeconds==seconds && !_millis)
return _lastResult;
Date d = new Date(inDate);
// Check if we need a new format string
long minutes = seconds/60;
if (_lastMinutes != minutes)
{
_lastMinutes = minutes;
_secFormatString=_minFormat.format(d);
int i;
int l;
if (_millis)
{
i=_secFormatString.indexOf("ss.SSS");
l=6;
}
else
{
i=_secFormatString.indexOf("ss");
l=2;
}
_secFormatString0=_secFormatString.substring(0,i);
_secFormatString1=_secFormatString.substring(i+l);
}
// Always format if we get here
_lastSeconds = seconds;
StringBuffer sb=new StringBuffer(_secFormatString.length());
synchronized(sb)
{
sb.append(_secFormatString0);
int s=(int)(seconds%60);
if (s<10)
sb.append('0');
sb.append(s);
if (_millis)
{
long millis = inDate%1000;
if (millis<10)
sb.append(".00");
else if (millis<100)
sb.append(".0");
else
sb.append('.');
sb.append(millis);
}
sb.append(_secFormatString1);
_lastResult=sb.toString();
}
return _lastResult;
}
/* ------------------------------------------------------------ */
/** Format to string buffer.
* @param inDate Date the format
* @param buffer StringBuffer
*/
public void format(long inDate, StringBuffer buffer)
{
buffer.append(format(inDate));
}
/* ------------------------------------------------------------ */
/** Get the format.
*/
public SimpleDateFormat getFormat()
{
return _minFormat;
}
/* ------------------------------------------------------------ */
public String getFormatString()
{
return _formatString;
}
/* ------------------------------------------------------------ */
public String now()
{
return format(System.currentTimeMillis());
}
}
Related examples in the same category
| 1. | Date Era change | |  |
| 2. | Date Format | | |
| 3. | The Time and Date Format Suffixes | | |
| 4. | Display standard 12-hour time format | | |
| 5. | Display complete time and date information | | |
| 6. | Display just hour and minute | | |
| 7. | Display month by name and number | | |
| 8. | DateFormat.getDateInstance(DateFormat.SHORT) | | |
| 9. | Use relative indexes to simplify the creation of a custom time and date format. | | |
| 10. | Date Format with Locale | |  |
| 11. | Date Format Symbols | |  |
| 12. | Decimal Format with different Symbols | |  |
| 13. | Date format: "dd.MM.yy", "yyyy.MM.dd G 'at' hh:mm:ss z","EEE, MMM d, ''yy", "h:mm a", "H:mm", "H:mm:ss:SSS", "K:mm a,z","yyyy.MMMMM.dd GGG hh:mm aaa" | |  |
| 14. | SimpleDateFormat.getAvailableLocales | |  |
| 15. | DateFormat.SHORT | | |
| 16. | This is same as MEDIUM: DateFormat.getDateInstance().format(new Date()) | | |
| 17. | This is same as MEDIUM: DateFormat.getDateInstance(DateFormat.DEFAULT).format(new Date()) | | |
| 18. | DateFormat.getTimeInstance(DateFormat.MEDIUM, Locale.CANADA).format(new Date()) | | |
| 19. | DateFormat.getTimeInstance(DateFormat.LONG, Locale.CANADA).format(new Date()) | | |
| 20. | DateFormat.getTimeInstance(DateFormat.FULL, Locale.CANADA).format(new Date()) | | |
| 21. | DateFormat.getTimeInstance(DateFormat.DEFAULT, Locale.CANADA).format(new Date()) | | |
| 22. | DateFormat.getDateInstance(DateFormat.LONG) | | |
| 23. | DateFormat.getTimeInstance(DateFormat.SHORT) | | |
| 24. | DateFormat.getTimeInstance(DateFormat.LONG) | | |
| 25. | Parse date string input with DateFormat.getTimeInstance(DateFormat.DEFAULT, Locale.CANADA) | | |
| 26. | Simple Date Format Demo | | |
| 27. | Format date in Medium format | | |
| 28. | Format date in Long format | | |
| 29. | Format date in Full format | | |
| 30. | Format date in Default format | | |
| 31. | Formatting day of week using SimpleDateFormat | | |
| 32. | Formatting day of week in EEEE format like Sunday, Monday etc. | | |
| 33. | Formatting day in d format like 1,2 etc | | |
| 34. | Formatting day in dd format like 01, 02 etc. | | |
| 35. | Format hour in h (1-12 in AM/PM) format like 1, 2..12. | | |
| 36. | Format hour in hh (01-12 in AM/PM) format like 01, 02..12. | | |
| 37. | Format hour in H (0-23) format like 0, 1...23. | | |
| 38. | Format hour in HH (00-23) format like 00, 01..23. | | |
| 39. | Format hour in k (1-24) format like 1, 2..24. | | |
| 40. | Format hour in kk (01-24) format like 01, 02..24. | | |
| 41. | Format hour in K (0-11 in AM/PM) format like 0, 1..11. | | |
| 42. | Format hour in KK (00-11) format like 00, 01,..11. | | |
| 43. | Formatting minute in m format like 1,2 etc. | | |
| 44. | Format minutes in mm format like 01, 02 etc. | | |
| 45. | Format month in M format like 1,2 etc | | |
| 46. | Format Month in MM format like 01, 02 etc. | | |
| 47. | Format Month in MMM format like Jan, Feb etc. | | |
| 48. | Format Month in MMMM format like January, February etc. | | |
| 49. | Format seconds in s format like 1,2 etc. | | |
| 50. | Format seconds in ss format like 01, 02 etc. | | |
| 51. | Format date in dd/mm/yyyy format | | |
| 52. | Format date in mm-dd-yyyy hh:mm:ss format | | |
| 53. | Format year in yy format like 07, 08 etc | | |
| 54. | Format year in yyyy format like 2007, 2008 etc. | | |
| 55. | new SimpleDateFormat("hh") | | |
| 56. | new SimpleDateFormat("H") // The hour (0-23) | | |
| 57. | new SimpleDateFormat("m"): The minutes | | |
| 58. | new SimpleDateFormat("mm") | | |
| 59. | SimpleDateFormat("MM"): number based month value | | |
| 60. | new SimpleDateFormat("s"): The seconds | | |
| 61. | new SimpleDateFormat("ss") | | |
| 62. | new SimpleDateFormat("a"): The am/pm marker | | |
| 63. | new SimpleDateFormat("z"): The time zone | | |
| 64. | new SimpleDateFormat("zzzz") | | |
| 65. | new SimpleDateFormat("Z") | | |
| 66. | new SimpleDateFormat("hh:mm:ss a") | | |
| 67. | new SimpleDateFormat("HH.mm.ss") | | |
| 68. | new SimpleDateFormat("HH:mm:ss Z") | | |
| 69. | SimpleDateFormat("MM/dd/yy") | | |
| 70. | SimpleDateFormat("dd-MMM-yy") | | |
| 71. | SimpleDateFormat("E, dd MMM yyyy HH:mm:ss Z") | | |
| 72. | SimpleDateFormat("yyyy") | | |
| 73. | The month: SimpleDateFormat("M") | | |
| 74. | Three letter-month value: SimpleDateFormat("MMM") | | |
| 75. | Full length of month name: SimpleDateFormat("MMMM") | | |
| 76. | The day number: SimpleDateFormat("d") | | |
| 77. | Two digits day number: SimpleDateFormat("dd") | | |
| 78. | The day in week: SimpleDateFormat("E") | | |
| 79. | Full day name: SimpleDateFormat("EEEE") | | |
| 80. | Add AM PM to time using SimpleDateFormat | | |
| 81. | Simply format a date as "YYYYMMDD" | | |
| 82. | Java SimpleDateFormat Class Example("MM/dd/yyyy") | | |
| 83. | The format used is EEE, dd MMM yyyy HH:mm:ss Z in US locale. | | |
| 84. | Date Formatting and Localization | | |
| 85. | Get a List of Short Month Names | | |
| 86. | Get a List of Weekday Names | | |
| 87. | Get a List of Short Weekday Names | | |
| 88. | Change date formatting symbols | | |
| 89. | An alternate way to get week days symbols | | |
| 90. | ISO8601 formatter for date-time without time zone.The format used is yyyy-MM-dd'T'HH:mm:ss. | | |
| 91. | ISO8601 formatter for date-time with time zone. The format used is yyyy-MM-dd'T'HH:mm:ssZZ. | | |
| 92. | Parsing custom formatted date string into Date object using SimpleDateFormat | | |
| 93. | Parse with a custom format | | |
| 94. | Parsing the Time Using a Custom Format | | |
| 95. | Parse with a default format | | |
| 96. | Parse a date and time | | |
| 97. | Parse string date value input with SimpleDateFormat("E, dd MMM yyyy HH:mm:ss Z") | | |
| 98. | Parse string date value input with SimpleDateFormat("dd-MMM-yy") | | |
| 99. | Parse string date value with default format: DateFormat.getDateInstance(DateFormat.DEFAULT) | | |
| 100. | Find the current date format | | |
| 101. | Time format viewer | | |
| 102. | Date format viewer | | |
| 103. | Returns a String in the format Xhrs, Ymins, Z sec, for the time difference between two times | | |
| 104. | format Duration | | |
| 105. | Get Date Suffix | | |
| 106. | ISO8601 Date Format | | |
| 107. | Explode a date in 8 digit format into the three components. | | |
| 108. | Date To Iso Date Time | | |
| 109. | Iso Date Time To Date | | |
| 110. | Gets formatted time | | |
| 111. | Format Time To 2 Digits | | |
| 112. | Time formatting utility. | | |
| 113. | ISO 8601 BASIC date format | | |
| 114. | Format As MySQL Datetime | | |
| 115. | new SimpleDateFormat( "EEE MMM d HH:mm:ss z yyyy", Locale.UK ) | | |
| 116. | Date parser for the ISO 8601 format. | | |
| 117. | Parse W3C Date format | | |
| 118. | Pack/Unpacks date stored in kdb format | | |
| 119. | Provides preset formatting for Dates. All dates are returned as GMT | | |
| 120. | Parse RSS date format to Date object. | | |
| 121. | Date format for face book | | |
| 122. | FastDateFormat is a fast and thread-safe version of java.text.SimpleDateFormat. | | |
| 123. | Date format and parse Util | | |
| 124. | XSD Date Time | | |
| 125. | Return a String value of Now() in a specify format | | |
| 126. | Format data to string with specified style. | | |
| 127. | extends Formatter | | |